Paper Info
Title
Targeted Grassland Monitoring at Parcel Level Using Sentinels, Street-Level Images and Field Observations.
Abstract
The introduction of high-resolution Sentinels combined with the use of high-quality digital agricultural parcel registration systems is driving the move towards at-parcel agricultural monitoring. The European Union's Common Agricultural Policy (CAP) has introduced the concept of CAP monitoring to help simplify the management and control of farmers' parcel declarations for area support measures. This study proposes a proof of concept of this monitoring approach introducing and applying the concept of markers'. Using Sentinel-1- and -2-derived (S1 and S2) markers, we evaluate parcels declared as grassland in the Gelderse Vallei in the Netherlands covering more than 15,000 parcels. The satellite markersrespectively based on crop-type deep learning classification using S1 backscattering and coherence data and on detecting bare soil with S2 during the growing seasonaim to identify grassland-declared parcels for which (1) the marker suggests another crop type or (2) which appear to have been ploughed during the year. Subsequently, a field-survey was carried out in October 2017 to target the parcels identified and to build a relevant ground-truth sample of the area. For the latter purpose, we used a high-definition camera mounted on the roof of a car to continuously sample geo-tagged digital imagery, as well as an app-based approach to identify the targeted fields. Depending on which satellite-based marker or combination of markers is used, the number of parcels identified ranged from 2.57% (marked by both the S1 and S2 markers) to 17.12% of the total of 11,773 parcels declared as grassland. After confirming with the ground-truth, parcels flagged by the combined S1 and S2 marker were robustly detected as non-grassland parcels (F-score = 0.9). In addition, the study demonstrated that street-level imagery collection could improve collection efficiency by a factor seven compared to field visits (1411 parcels/day vs. 217 parcels/day) while keeping an overall accuracy of about 90% compared to the ground-truth. This proposed way of collecting in situ data is suitable for the training and validating of high resolution remote sensing approaches for agricultural monitoring. Timely country-wide wall-to-wall parcel-level monitoring and targeted in-season parcel surveying will increase the efficiency and effectiveness of monitoring and implementing agricultural policies.
Year
DOI
Venue
2018
10.3390/rs10081300
REMOTE SENSING
Keywords
Field
DocType
meadow,grassland,Sentinel-1,Sentinel-2,crowdsourcing,deep learning,geo-tagged street-level pictures,CAP,agriculture,TensorFlow
Remote sensing,Grassland,Geology
Journal
Volume
Issue
ISSN
10
8
2072-4292
Citations 
PageRank 
References 
3
0.46
8
Authors
3
Name
Order
Citations
PageRank
Raphaël d'Andrimont130.46
Guido Lemoine222736.45
Marijn Van der Velde31217.94